Gorgeous city parks, lucky cats and much more in MNN's week in review

From the best big-city parks to great places to go for a trail run, we've got plenty of ideas in this week's environmental roundup.

• It's no surprise that many runners head to the hills to get away from the distractions of modern life — like uneven sidewalks and automobiles. We've pulled together seven of the best running trails in the U.S. — for those who prefer wildlife over wild drivers.

• Speaking of getting away from it all, these nine parks in international cities should be on every tourist's to-do list. (That's Central Park pictured above left.)

• We've got a good news/bad news approach to cats this week, but let's start with the positive: This gallery of cat rescues — we like to call it cat-astrophe averted! — will make you smile. So what's the bad news? A new study finds that outdoor cats are prolific killers. The numbers are stunning.

• Speaking of the dark side, the introduction of Beyond Meat, an imitation chicken food, sparked a lot of conversation on the Web this week. In response, we look at the ingredient list of five fake foods. (Fair warning that it may prompt you to toss some things from your fridge.)

• As kids head back to school, they're likely to encounter a dog or two as they walk through the neighborhood. Here's what they need to know to keep that interaction fun and safe.

• We wondered about all the different kinds of yoga available, and Starre Vartan decided to spell it out. Here's her first installment: What is Vinyasa yoga?

• Want to attend a food swap and come out ahead? The challenge is to hit the sweet spot between tastiness and thriftiness, creating a dish that others will covet. Here are five recipes that meet the challenge.

• Everyone loves a rainbow, but do you know the science behind it? Advice expert Chanie Kirschner does some research and comes up with some interesting information.

• Deforestation is a word you hear far too often in this line of work, and sometimes the meaning gets muddled. These satellite photos bring Amazon deforestation clearly into focus.

Plus: Don't miss this collection of Olympstagrams from London, including a bigger version of the photo below. Have a great week!